'Data file len-rpar.dat: Ray parameters for two-point ray tracing' 2 -1 -2 -1 0.001 0.002 0 0 0 / (ISRFR,ISRFX1,ISRFX2,NREC,XERR,AERR,...) 'len-rec.dat' / (File with receiver coordinates) 0.0000 -1.3090 3.1416 -1.3090 0.0000 1.3090 18 30 1 / / / / / / ========================================================================